BECKLEY, W.Va. — The stately, wood-paneled chamber in the federal building here unsettled Gary Fox and his wife, Mary. Fox was used to the dusty caverns of the mines in the southern part of the state, where he’d spent more than 25 years working underground in the heart of Appalachian coal country. They had never been in a courtroom before.

It had been at least 15 years since Fox first noticed signs of black lung disease. It started with shortness of breath. Then a cough that yielded black mucus. By 1999, his symptoms convinced him to apply for federal benefits. A doctor certified by the U.S. Department of Labor examined him and diagnosed the most severe form of the disease, known as complicated coal workers’ pneumoconiosis. The government ordered his employer, a subsidiary of behemoth Massey Energy Co., to begin paying him monthly benefits, but, as is almost always the case, the company appealed.

Gary and Mary now found themselves visitors in a foreign world — one populated by administrative law judges who must make sense of reams of medical evidence, sophisticated legal arguments and arcane rules; coal-company lawyers who specialize in the vagaries of the system and know how to attack claims; and doctors who consistently find cause to diagnose almost anything but black lung.

Among the most prominent denizens of this world are the attorneys in the federal black lung unit of the law firm Jackson Kelly PLLC. For almost two centuries, the firm has served the coal industry. It is the go-to place for many of the industry’s giants when they want to beat back a miner’s claim for benefits.

Jackson Kelly, with offices throughout Appalachia, as well as in Denver and Washington, D.C., defends companies accused of polluting the environment, marketing dangerous drugs or discriminating against workers. It helps corporations avoid regulations, drafts bills and lobbies legislators. Its bailiwick, though, is mining.U.S. News & World Report recently named it the nation’s top firm in mining law. Jackson Kelly’s name is on the lips of clinic workers, miners and lawyers throughout Appalachia and is emblazoned atop an office overlooking the Monongahela River in Morgantown, W.Va.

Now, with government scientists documenting a resurgence of black lung disease, the firm’s legal strategy — including, the Center for Public Integrity found, a record of withholding evidence — could have significant consequences for sick miners and their families.

On this September morning in 2000, in the courthouse named for longtime Sen. Robert C. Byrd, an experienced Jackson Kelly attorney sat at one table. At the other, Gary and Mary sat alone, having tried unsuccessfully to find a lawyer. This imbalance is not uncommon, as claimants’ attorneys have fled the federal black lung system in recent decades. Time and money are on the side of the coal company, which can hire scads of experts and drag cases out for years or decades. Miners’ lawyers are legally barred from charging claimants any fees, and the payoff, in the rare event of a win, is relatively meager.

Tall, lean and stoic, Fox, then 50, answered the judge’s questions with quiet deference — “Yes, sir” and “No, sir.” His brief testimony, along with the report from the examination paid for by the Labor Department, constituted virtually his entire case. Then it was Jackson Kelly’s turn. Exhibit after exhibit became part of the record — medical reports, depositions, résumés of eminent doctors who’d reviewed the evidence.

More important, however, was what didn’t make it into the record. Two years earlier, doctors had removed a suspicious mass from Fox’s lung. The purpose had been to rule out cancer, which the hospital’s pathologist had done. There is no evidence he looked for signs of black lung, or even that he knew Fox was a miner. Unknown to Fox, however, Jackson Kelly had obtained the slides of his lung tissue and sent them to two pathologists in its usual stable — doctors whose opinions typically supported the firm’s case.

This time Jackson Kelly didn’t get the answer it wanted. Both pathologists wrote reports indicating the mass likely was complicated black lung — a finding that, if credited by the judge, automatically would have won the case for Fox.

The firm’s lawyers could have accepted the opinions of the doctors they’d relied on so many times before. They could have conceded that Gary’s case had merit and agreed to pay him and Mary $704.30 a month, allowing him to escape the dust destroying his lungs. Even if they chose to fight the claim, they could have allowed their experts to see all of the pathology reports as they formed their opinions.

None of that is what the lawyers at Jackson Kelly did. Instead, the firm withheld the reports; Fox, the judge and the firm’s own consulting doctors had no idea they existed. In the months that followed, a team of Jackson Kelly lawyers built a case around the hospital pathologist’s report and its vague diagnosis of “inflammatory pseudotumor.” They encouraged the court and their own consulting doctors to view the report as the sole, definitive account of what Fox’s lung tissue revealed. Even one of the doctors retained by Jackson Kelly originally thought Fox had black lung. After being given the pathologist’s report, he changed his mind.

Relying heavily on the pathology report, a judge denied Fox’s claim for benefits in 2001, leaving him few options. He had a family to support, and he needed health insurance because Mary had a chronic illness. He went back to the mine, his health deteriorating. For years, no one but the firm knew of the powerful evidence that he had the severe disease and should get out of the mine’s dusty atmosphere immediately.

What happened to Gary Fox was not the result of a rogue attorney or singular circumstances. It was part of a cutthroat approach to fighting miners’ claims that Jackson Kelly has employed to great effect for decades, an investigation by the Center for Public Integrity has found. Some of the firm’s tactics go beyond aggressive advocacy, crossing into unethical behavior, according to current and former judges, lawyers and state disciplinary officials. As a result, sick and dying miners have been denied the modest benefits and affordable medical care that would allow them to survive and support their families.

The role of lawyers in orchestrating sophisticated legal strategies to defeat claims for benefits is just the first chapter in the story of a system in which well-paid specialists thrive as miners struggle, the Center’s yearlong investigation, Breathless and Burdened, found. Coal companies rely on a cadre of doctors with prestigious affiliations, including a unit at the nation’s top-ranked hospital, to trump the opinions of miners’ physicians. Experts for hire continue a century-old tradition: denying scientific evidence that black lung can assume different appearances in different people, locking an entire class of sick miners out of the benefits system.

Jackson Kelly, documents show, over the years has withheld unfavorable evidence and shaped the opinions of its reviewing doctors by providing only what it wanted them to see. Miners, often lacking equally savvy lawyers or even any representation, had virtually no way of knowing this evidence existed, let alone the wherewithal to obtain it.

In the rare cases in which miners’ lawyers have pushed for access to these materials and a judge has ordered disclosure, Jackson Kelly has fought back aggressively, arguing that it has the right to withhold them. The firm has asked higher courts to intervene and accused judges of bias. It has defied court orders, knowing administrative law judges have no contempt powers to enforce their commands, or conceded the case rather than turn over evidence.

In published decisions, judges have called the firm’s defenses of its actions “ludicrous” and “flimsy at best.” “This is pretty shocking,” a current judge wrote of Jackson Kelly’s behavior in a 2009 email obtained by the Center. “It appears to represent a long-standing pattern of misconduct.”

Still, judges generally haven’t been receptive to arguments that Jackson Kelly’s handling of a particular case is symptomatic of anything broader or that disciplinary action is warranted.

Fox’s case, still unresolved, could change that. A judge deemed Jackson Kelly’s actions in the case a fraudulent scheme that threatened the integrity of the judicial system. A split appeals court vacated that ruling, and the decision is now on appeal. After the Center contacted the West Virginia Office of Disciplinary Counsel and asked whether action would be taken, the office opened investigations into three Jackson Kelly lawyers who were involved in Fox’s case. To date, they have not been charged with any wrongdoing.

The judge who denied Fox’s claim in 2001, Edward Terhune Miller, recently retired and, in an interview with the Center, learned what had been shielded from him more than a decade earlier. His eyes widened, and, for a moment, he was speechless.

Jackson Kelly’s general counsel, on behalf of the firm and the individual attorneys contacted by the Center, declined repeated interview requests and would not discuss specific cases or general practices. In court filings, the firm has argued that there is nothing wrong with its approach and that its proper role is to submit the evidence most favorable to its clients.

A spokesman for Alpha Natural Resources, which purchased Massey Energy and is now opposing Fox on appeal, declined to comment on the case while it is ongoing.

Until now, Jackson Kelly’s conduct in black lung cases has remained largely buried in voluminous files that are confidential because of the private medical and financial information they contain.

Over the past year, however, the Center has identified key cases and obtained written permission from miners or their surviving family members to view their entire case files. These 15 files span 40 years and include hundreds of thousands of pages. The Center also reviewed the limited publicly available information on dozens more of the firm’s cases.